The Significance of Changes in Serum Prostate Specific Antigen Levels after a Transurethral Resection of the Prostate

Won, Jong Jin; Chung, Hyun Chul; Song, Jae Mann

Abstract

PURPOSE: The serum prostate specific antigen (PSA) level is known to be related with the total prostate and cancer volumes. After a transurethral resection of the prostate (TURP) in patients with benign prostatic hyperplasia (BPH), a decrease in the serum PSA level is expected. We investigated the relationship between the resected prostate specimen weight and serum PSA level.
MATERIALS AND METHODS
Between July 1998 and March 2003, 372 patients underwent a TURP for the treatment BPH. We performed studies, including digital rectal examination, urinary flow rate, international prostate symptom score, serum PSA levels, and transrectal ultrasound (TRUS) pre-and post-operatively. We compared the resected specimen weight of the prostate with the changes in the serum PSA level using correlation and regression tests as statistical methods.
RESULTS
Removal of 1gm of BPH tissue decreased the serum PSA the average level by 0.45 0.25ng/ml. In patients with BPH, there was a strong statistical correlation and a direct proportionality between the resected specimen weight and changes in the serum PSA level (p<0.05). Using the above mentioned statistical methods, the formula y=2.389+0.158x (x= resected specimen weight, y=changes in serum PSA levels) was derived. However, there was no statistical correlation between the two factors in prostate cancer patients.
CONCLUSIONS
An elevated serum PSA level in patients with BPH is mainly caused by the enlargement of the prostate transition zone. A statistically significant difference was noted between the pre-and post-operative serum PSA levels. However, in patients with prostate cancer, the serum PSA levels showed various postoperative changes. Some patients that underwent a TURP for BPH showed no match on the previously-mentioned formula, and these patients should be carefully followed up, with serum PSA level check-ups and/or a prostate biopsy considered.